VM24 - Colonoscopy Maneuvers for Trainees

Purpose/Background: General surgery residents are required to perform 50 colonoscopies per the ACGME defined category minimum. Learning the procedure can be challenging for trainees, and it can be difficult for residents to learn how to perform a successful colonoscopy from anal intubation to terminal ileum due to the steep learning curve.

Methods/Interventions: To combat the learning curve, we propose a step-up approach to serve as a toolkit for residents to pull from in order to progress toward the cecum during a colonoscopy. This toolkit consists of key maneuvers that can be utilized during different portions of the procedure.

Results/Outcomes: Key maneuvers that we will discuss include tip deflection, torque, dithering, aspiration, hooking and straightening, and slide-by technique. The first two maneuvers focus on the basic movements of the colonoscope. The goal of tip deflection is to keep the lumen in view. The larger outer wheel controls vertical deflection, while the smaller inner wheel controls lateral deflection. The tip is in the neutral position when the letters on both wheels are pointed upward. The wheels can be used in combination. Torque is also a key technique, particularly in the sigmoid. Clockwise torque straightens the colonoscope, which accordionizes the sigmoid around the scope, moving the tip proximally relative to the surrounding sigmoid. Loops often form in the sigmoid, at which time the proceduralist should pull back the shaft and apply clockwise torque to remove the loop. Counterclockwise torque, on the other hand, would exacerbate the curve of the colonoscope. This creates the effect of paradoxical motion, which causes the tip to withdraw relative to the surrounding colon. Torquing to keep the lumen in view can be more effective than deflecting the tip, and torque in combination with one deflection wheel is often more effective than a combination of both wheels.

The next two maneuvers take advantage of the ability to create space within the lumen around the colonoscope. Dithering is the action of rapidly shaking the colonoscope. This creates a sinusoidal wave, which separates the colonoscope into the lumen away from the surrounding mucosa, making it easier to advance. Dithering helps pleat the colon onto the colonoscope, shortening the length of the bowel surrounding the scope. Aspiration involves first distending the colon with insufflation then suctioning to aspirate the air from the lumen. When the surrounding colon is no longer distended, the length should decrease. This is especially useful in the ascending, or right, colon.

The final two maneuvers are considered to be more advanced. Hooking and straightening can be particularly useful in a tortuous sigmoid. The scope tip is turned thirty to ninety degrees across the sharp angle of a mucosal fold. The scope is then slowly withdrawn several centimeters, catching the turn of the scope around the angle of the turn in the colon, which straightens the angle as the scope is pulled back. The scope can then be advanced forward. Slide-by is one of the more advanced techniques that a trainee may be exposed to, and beginners should not attempt it due to the high risk of iatrogenic perforation. It is a blind technique in which the proceduralist pushes the tip forward in the anticipated direction of the lumen. It is most commonly applied in the rectosigmoid.

Conclusion/Discussion: Several maneuvers can help a trainee progress toward the cecum during early colonoscopies. Having these maneuvers available may help residents be more successful at colonoscopy during their training.